Form dressing device



Filed Jan. 30, 1958 W. KLAASSEN FORM DRESSING DEVICE 3 Sheets-Sheet 2 'wA f INVENTOR. a/IM iasw Ot. 20, 1959 w. KLAAssEN 909,168

FORM DRESSING DEVICE Filed Jan. 30, 1958 3 Shee'cs--Sheei'fv :E LE- LVECE I /77 INVENTOR. 7

United States Patent O FORM DRESSING DEVICE William Klaassen, Brooklyn, Mich., assignor of one-third to Jerome M. Terhaar and one-third to George E. Howell Application January 30, 1958, Serial No. 712,130

7 Claims. (Cl. 12511) This invention relates to form dressing devices and more particularly to a device capable of shaping the cutting periphery of a grinding wheel to embody a desired contour through the actuation of a single control element whereby articles embodying complex arcuate and plane surfaces may readily be formed.

Conventional devices for dressing grinding wheels require two control elements or a readjustment of the setting in order to form a combined at or plane and arcuate surface. Such devices are limited to cutting either a plane surface or an arcuate surface through one manipulation of a control element.

The disadvantages of such devices reside inflack of accuracy and high operating expense. When two control elements or two set-ups are required to make one cut, the inaccuracies inherent in each control element or the set-up process are compounded. Further, when the travel of the cutting tool, usually a diamond tool7` is stopped momentarily to operate the second control the tool heats up and an undesirable groove or break is formed on the grinding wheel being dressed. The temperature `increase of the diamond dining the stoppage also causes increased wear of the tool leading to a de' creased tool life.

According to the present invention a device is provided which will form a combined arcuate and plane surface on a grinding wheel by the actuation of a single control element. Attempts have heretofore been made to develop such a form dressing device. However the proposed form dressers have been devices with complicated structures which are relatively expensive to manufacture and maintain. The present device has a relatively simple structure and is efficient and dependable in operation.

It is therefore a principal object of my invention to provide a form dressing device which is capable of dressing a plane surface, an arcuate surface, or a combination of a plane and arcuate surface on a grinding wheel by the actuation of a single control element.

Another object of this invention is the provision of a form dresser capable of cutting arcuate and plane surfaces wherein the length of the arc and the inclination of the plane may be accurately adjusted over a wide range.

Another object is the provision of such a device which is capable of forming an arcuate surface having a plane surface tangent to each end of the arc.

An important feature of my invention is the provision of a rotating head which carries' a tool holding carriage mounted to alternately rotate with the head and to slide in a straight line and which is locked against such sliding during head rotation. 7

Another feature is the provision of a single crank element to actuate the head and carriage through the rotating and sliding movements.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of 2,909,168 Patented Oct. 20, 1959 ICC Fig. 2 is a rear elevational View of the form dressing device of Fig. l.

Fig. 3 is a sectional view taken substantially along the line 3 3 of Fig. l looking in thedirection of the arrows. Fig. 4 is a sectional View taken substantially along the l line 4 4 of Fig. 3 looking in the direction of the arrows.

Fig. 5 is a sectional view taken substantially along the line 5-5 of Fig. 3 looking in the direction of the arrows.

Fig. 6 is a sectional View taken substantially along thev line 6-6 of Fig. 3 looking in the direction of thearrows.

Fig. 7 is a View in perspective of the carriage utilized in the present invention.

Fig. 8 is a sectional View illustrating one application of the present invention showing a grinding wheel dressed with a concave surface having a plane surface tangent to each end of the arcuate surface.

Fig. 9 is a sectional View of a grinding wheel illustrating another application of the present invention with the arcuate surface being convex.

Fig. l() is a view similar to Fig. 8 illustrating a concave dressing which is displaced from the center of the Wheel and is at an angle to the plane of the wheel.

Fig. ll isa sectional View of a grinding wheel illustrating a surface having a concave portion with non-tangent at surfaces depending therefrom.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As best seen in Figs. l, 2 and 3, the form dressing device comprises a housing 10 in which is journaled a rotatable head 12. Mounted in the head 12 is a slidable generally rectangular carriage 14 which carries a dressing arm 16. Iournaled within the head l2 is a crank arrangement 18 which is operatively connected to the carriage 14. Stop means are mounted within the housing 10 which cooperate with stop means mounted on the head l2 and carriage i4 to provide an alternate sliding movement of the carriage 14 and rotative movement of the head 12 and carriage 14. Circular indexing means are provided on a portion of the head 12 extending outside of the housing 10 to accurately preset the extent of the rotative andsliding movements of the head 12 and carriage 14.

The housing 10 comprises a front plate 2li and a rear enclosure 22 mounted on a suitable base 24 by means of machine screws 26. The plate 20 and enclosure 22 are secured together by means of a plurality of machine screws 28. The front plate 20 is provided with a central opening 32 which allows one end of the arm 16 to extend into the housing 1li to engage the carriage 14. A central opening 34 is also provided in the rear wall 30 of the enclosure 22 for the purpose of journaling an outwardly extending portion of the head l2.

An annular front ring support plate 36 is secured on the inner surface of the plate 20 within a circular recess 38 'by means of a plurality of machine screws 40.

annular rear ring support plate 42 is secured within the housing l10 on the inner surface of the rear wall 30 by means of a plurality of machine screws 44. The support plate 42 has a central annular ange 46 which extends through the opening 34 for a short distance outside of the housing 10.- Ituis" tofbe noted that while the plates 36, 42 are shown as separate parts, they could be formed integrally with the housing 10.

A front stop ring 48 is rotatably mounted on a shouldei* 50 formed by an inwardly projecting annular flange 52 provided centrally onI the front ring support plate 36. A corresponding rear stop ring 54 is rotatably mounted onthe outer'periphery of the rear ring support plate 42.

Each stop ring 48, 54 is provided with a releasable brake arrangement to permit the stopv rings 48, 54' to be rotated so as to angularly adjust stop keys 56, 58 mounted on the inner side yfaces of the rings 48, 54. The keys- 56, 58 are provided with finger elements 49, 51 for the purpose of engaging corresponding stop means upon the head 12 as will be hereinafter explained. Since the brake arrangement is similar for each ring 48, 54, the followingV description of the 'brake for the ring 54- also applies to the brake for the ring 48.

The ring 54 is provided with a peripheral groove 68 which extends around the entire circumference. As may be seen in Fig. 4, a exible wire or brake band 62, whichseats in the groove 60, is wrapped once around the ring. 54. One end of the Wire 62 extends tangentially from the ring 54 and is attached to a pin 64 which projects from the rear housing wall 30. The other end of the wire 62 also extends tangentially from the ring 54 and' is attached to a dog legA lever 66. The lever 66 is pivotally mounted on the Wall 30 in contact with the leading end of a bolt 68. The bolt 68 threadingly engages a threaded opening 70 which extends through the enclosure 22 adjacent the rear wall 30. Tension on the wire 62 is consequently controlledA by threading the bolt 68 in or out. The braking action issimilar to that of a band type brake. The ring 54 may be locked against rotation or the wire 62 may be loosened so that the ring 54 is free to rotate about the rear ring support plate 42 for adjustment of the stop key 58.

The stop rings 48, 54 encircle the rotatable head 152 which, as previously mentioned, is journaled' Within the housing 10. The head 12 comprises a front annular bearing plate V74 anda rear annular bearing plate 76 which are secured, by means of machine screws 82, to spaced way blocks 78, 80.

The head 12 is journaled in the housing 10 by means of ball bearings 90 and roller bearings 92. The ball bearings 90 are received in a passageway 88 formed by the inwardly extending surface 86 of the bearing plate 74, the front stop ring 48 and the frontA ring support plate 36. The opposite side of the head 12 has a circular ange or shaft 94 which projects outwardly from the center of the rear bearing plate 76 and is supported by the roller bearings 92. The inner race 96 of the bearings 92 is held in place by means of a circular shoulder 98 provided on the flange 94. The bearing 92 is held against sidewise thrust in the opposite direction by means of an annular plate 100 which abuts against the outer' race 102. The periphery of the plate 100 is threaded to engage the threaded portion 104 provided on the inner periphery of the flange 46 of the' rear ring support plate 42. The plate 100 may be provided with a dust seal element 106 seated within a circular groove 108 provided in the central opening 110 of the plate 100.

Two retainer rings 75, 77 are rotatably mounted in the head 12 by means of recesses 79, 81 formed ou the inner faces of bearing plates 74, 76 adjacent to the peripheries thereof. The rings 75, 77 are held in place by the abutting way blocks 78, 80. The distal portion of the rings 75, 77 extends beyond the outer periphery of theA head 12 and into recesses 83, 85 provided in the stop rings 48, 54. A lug 87, 89 projects inwardly from the inner facing of each of the respective rings 75, 77 adjacent the outer periphery thereof and is so proportioned as to clear the head 12 but engage a respective stop key 56, 58. A at spring 91 extends between the rings 48, 54 and is fixed to pivot about its center.

operates to maintain the rings75,.77 in a carriage locking position.

The rectangular opening 84 formed by the inner surfaces of the bearing plates 74, 76 and the spaced way blocks 78, slidingly receives the carriage 14 by means of ball bearings 112. Longitudinal grooves 114 in the sides of the carriage 14 serve as the inner bearing raceways and grooves in the. detachable races 118 serve as the outer raceways. The races 118 are seated in recesses 12'2, 124' provided in the way blocks 78,v 80. The pressure of the races 1'18 against the bearings 112y and vbearing retainers 113 may be adjusted by means of a plurality off set'- screws 126, 128 which extend? through the respective way blocks 78,A 80.

The carriage 1`4, as best seen in Fig. 7, comprises a generally rectangular block. The ends 130, 132 of the carriage 14 are circular to allow -for clearance of the stop keys 56, 58.. Longitudinal slots134, 136 are provided on each front andi rear face 135, 137.` The slots 134;. 136 are Wider' than the keys` 56,- 58 and are also wider than the combined width of the lugs 87, 89 andf lingers 49, 51 inl order to slidably receive these elements during reciprocation as wiil be hereinafter more fully described. Lateral slots 138, 140j areY providedl Iin1 the faces 135, 137 and. extend substantially through the longitudinal center thereof bisecting the slots 1=34, 136 at approximately right angles. A threaded opening 142 is provided at substantially the geometrical center of the carriage 14.

Although the carriage 14 is` seenA to be symmetrical about its longitudinalV axis and iny fact may be inserted into the head 12 without orientating the faces- 135, 137', the lateral slot 1-38 facing frontward is usedto center and hold the dressing arm 16 against movement relative to the carriage 14 and the slot 140' facing rearward' is used to operatively connect the crank mechanism 18 to the carriage 14.

Stopbars 144, 1-46 are mounted by means of machine screwsA 147 in recesses 148, 150 provided inl the carriage 1'4 adjacent the outer end of the slots 134, 136; The bars 144, 146 project for a distance from the end of the carriage 14 so as toengage stop keys 56, 58 as will later be described.

Carriage 14 as previously mentioned, carries the dressing arm" 1'6. Dressing arm 16l comprises a hub member 152 which is secured to the carriage 14 by means of a bolt 154 which engages the threaded opening 142.` A projecting key 156 on the hub 152 engages the lateral slot 138 thereby positively locking the hub 152 to the carriage 14. The hub 152 is. provided with an annular flange 158 which abuts against an annular dust seal plate 160 thus keeping an annular sealing element 162 in pressure contact with the front plate 20 of the housing 10.

The tool arm 164 is slidably mounted in a dovetail slot 166 of the hub 152 to provide an adjustable working radius for the cutting tool 178. The radius may be adjusted by means of a threaded stud 168 which is rotatably mounted in the arm 164 and threadingly engages a threaded opening 170 provided in a bracket 172 which is secured to a projection 174 of the hub 152. The arm 164 may be locked in place by means of the set screws 176 provided in the hub 152. A Vernier scale 17S may be provided on the arm 164 and hub 152 to give a rough measurement While setting the desired cutting radius. A ne measurement may be achieved by measuring the distance between a pair of pins 179, 181, by the use of a measuring device such as a micrometer. One pin 179 projects at right angles to the hub 152 and is positioned so that a line passing through the center thereof at right angles to the plane of the toolarm 164 will also pass through the center of the axis of rotation of -lthe arm 164. The pin 181 is mounted on the arm 164 at right angles thereto in line with the pin 179. The dis.-

tance between the pins 179, 181 is thus proportionate to the radius of the arm 164 and provides a means for accurate adjustment.

The crank mechanism 18 is provied to drive the arm 16 through a work cycle. 'I'he crank 18 comprises a knob 184 to which is secured a handle 186. The knob 184 is keyed to -a shaft 188 which is journaled within the shaft '94 of the rear bearing plate 76. The inner end of the shaft 188 is provided with a circular disk or crank arm 190 which is received, adjacent to the carriage 14, in the rectangular opening 84 of the head 12. A shoe 192 is pivotally mounted on the inner face of the disk 190 adjacent the periphery thereof. The shoe 192 rides in the lateral slot 140 so as to operatively connect the crank 18 to the carriage 14. The ends of the shoe 192 may be rounded to prevent jamming.

The operation of the dresser, including the rotation of the head 12, the reciprocation of the carriage 14 and the interrelationship of of the various stop means, is best illustrated in Figs. 3 and 6. A turning force applied to the handle 186 is transmitted to the shoe 192 by means of the knob 184, shaft 188 and disk 190. The shoe 192 will consequently bear against one of the side walls of the lateral slot 138 with a `force having a component tending to rotate the carriage 14 and head 12 and a component tending to slide the carriage 14 out of the head 12. During the Work cycle, either the head 12 will be free to rotate and the carriage 14- locked against reciprocation or the head 12 will be stopped from rotating in one direction and the carriage 14 free to reciprocate in one direction. The carriage 14 is always free to slide at the end of the head 12 rotation. Consequently, the carriage 14 andthe attached dressing arm 16 will be either rotated or reciprocated by means of the crank mechanism 18 depending upon the position of the head 12.

In the position shown in Fig. 6, the carriage 14 cannot reciprocate due to the obstructing lugs 87, 89. However, there is no obstruction to head 12 rotation. Therefore, for example, a clockwise force applied to the handle 186 will result in clockwise rotation of the head 12 and carriage 14. Continued clockwise rotation of the head 12 will eventually result in the finger 49 of the key 58 engaging the lug 89 and moving it, along with retainer ring 77, to a position over the slot 134 of the carriage 14, where the key 58 will engage the stop bar 144 preventing further clockwise rotation of the head 12. However, as shown in phantom in Fig. 6, the carriage 14 is now free to slide out of the head 12 towards the stop key 58 since the key 58 and lug 89 are now centered over the longitudinal slot 134. As the carriage 14 slides outward, the shoe 192 will slide along the slot 138 until the extent of travel is reached. At this point, the force on the handle 186 may be reversed, retracting the car-- riage 14 and rotating the head 12 in a counterclockwise direction until the lug 87 and stop bar 146 are engaged by the stop key 56, whereby the carriage 14 Will reciprocate in the opposite direction. The lugs 87, 89 will always resume their carriage 14 blocking positions after disengagement by the stop keys 56, 58 due to the action of the spring 91. When a lug 87, 89 is moved by a stop key 56, 58, the corresponding retainer ring 75, 77 is moved, thus deecting the spring 91. The spring 91 will return the retainer ring 75, 77 to approximately its original position when the stop key 56, 58 no longer bears against the engaged lug 87, 89.

The rotative and sliding motion of the carriage 14 results in a concurrent rotative and straight line motion of the attached dressing arm 16 to the end that the cutting tool 178 carried by the tool arm 164 may describe a path comprising a straight line portion, followed by an arc and then a second straight line portion. The arc may be convex or concave depending upon the location of the Wheel in reference to the circle described by the tool 178 i.e. if the periphery of the wheel is outside the circle, the arc will be concave, if the periphery is within the circle, the arc Will be convex. The tool 178 must either be removed and re-inserted with the cutting point aimed in the opposite direction, or the arm 164 must be moved in the slot 166 so that the point of the tool 178 is above the axis of carriage rotation (assuming the tool 178 is mounted as in Fig. il) in order to change, for example, from a convex cut to a concave cut. In order that the straight line portion `of the cut be tangent to the arc, the dressing arm 16 must be rotated 180, e.g. Fig. l shows the dresser set up to form a surface as shown in Fig. 8 having a convex arcuate portion with at surfaces extending from the ends thereof and tangentl thereto, in order to form the concave arcuate portion with flat tangent surfaces extending lfrom the ends thereof as shown in Fig. 9, the arm 16 must be rotated 180 and the tool 178 mounted to point outwardly or the equivalent result may be obtained by shifting the tool arm 164 as explained above.

In operation, la grinding wheel is mounted in a xture to rotate at a relatively high rate. The depth of the cut is determined by the position of the wheel in relation to the tool 178. The carriage 14 is extended out of the head 12 to its limit position at the start of the cut, the cutting cycle thus comprising a first straight line portion, an arcuate portion and then a second straight line portion. The tool 178 is then moved through one cutting cycle by means of the single control element 186. Successive cuts may be taken by moving the wheel into the tool and repeating the cutting -action until the desired surface is formed.

While the forming of the surfaces of Figs. 8 and 9 has been described in detail, it is to be understood that other contours, such as an angularly olf-center surface as shown in Fig. l0, or a concave cut with non-tangent at surfaces depending therefrom as in Fig. ll, may also be formed. Other surfaces such for example, as entirely at or arcuate surfaces or an arcuate surface combined with one flat surface may be formed as desired.

An index plate 194 is provided for the purpose of accurately setting up the dresser to describe a predetermined path. The plate `194 is keyed to the outwardly extending portion of the shaft 94 and bears against the housing 28. As best seen in Fig. 2, the plate 194 may be calibrated in degrees in order to set up the arcuate portion of the cut. A Vernier scale `196 which may be calibrated in minutes is fastened to the housing 10 adjacent the index plate 194.

The dresser is setaup by rotating the head 12 until a stop key 56, S8 is engaged by a stop bar 144, 146. The corresponding brake band 62, 62 is released and the index plate 194 is rotated by means of a handle 198 until the desired setting is made. The brake band 62, 62 is then tightened and the procedure is repeated in the reverse direction. A recess 200, 202 is provided in each face y135, 137 of the carriage 14 adjacent the end opposite a stop bar `144, l146 so that the carriage 14 4will clear the respective oppositely disposed stop keys 56, 58 during the set-up procedure. The recesses 208, 202 also permit the carriage 14 to reciprocate when the stop key 56, 58 are so close together as to both fall within the width of the carriage 14.

The form dresser thus described is -seen tot be relatively simple to operate and adjust. The various parts each perform several functions thereby lessening the total number of parts. The necessity of gears and other complicated and expensive parts has been elimina-ted thereby reducing the cost of machining and fabricating the device. Since there are fewer parts, the maintenance of the dresser is appreciably reduced.

Having thus described my invention, I claim:

l. A form dressing device comprising a housing, a head rotatably journaled in the housing, a passageway extending centrally through the head at substantially right angles to the axis of head rotation, a generally rec- Z tangular carriage mounted. to slide in the passageway, meanson -the-headV releasably holding the carriage against movement-relative to the head, stop means on the housing to. limit. theextent. of rotation of the head and to release the.' carriage from the head at the limit of head rotation. andk to thereafter lockV `the head in-its limit position during sliding of the carriage, said stop means comprising a. pair of oppositely disposed stop rings rotatably mounted on the housing adjacent the inner faces thereof and. encircling said head, said rings being releasably v locked against, rotation-relative to the housing by means of a 'band brake mechanism, each of the rings carrying a stop key for the purpose of engaging the carriage and the releasable holding means on the head, a driving shaft journaled in the head coaxial therewith, a crank arm extending from the shaft, a Shoe pivotally mounted adjacent` the outer end of the crank arm, said shoe being slidingly connected to the carriage by means of a lateral slot in one face of the carriage thereby to rotate the head and carriage through the limits` of head rotation and to thereafter -actuate the carriage to slide relative to the head, a dresser armV mounted on the carriageand a cutting tool carried by the dresser arm.

2. A form dressing device as claimed in claim land further characterized in that the band brake mechanism comprises ya circumferential slot in the outer periphery of each of the stop rings, a flexible brake band extending around each of the rings and seated in the slots, the ends of each brake band being secured tothe housing, and means on the housing to tighten the bands.

3. A form dressing device as claimed in claim l` and further characterized in that an indexing mechanism is provided on the exterior of the housing to angularly set the stop rings,y comprising an annular calibrated member aixed to the head to rotate therewith, and a cooperating Vernier scale ixedly mounted on the housing ad.4

' jacent to the periphery of the calibrated member.

4. A form dressing device as claimed in claim 1 and further characterized in that the dresser arm is slidably adjustable on the carriage whereby to shorten or lengthen the radius of the circle described by the` cuttingtool when the head is rotated.

5. A. 'form dressing device comprising a housing, ahead rotatably journaled in the housing, a passageway extending centrally through the head at substantially right angles to the a-xis of head rotationfa generally rectangular carriage mounted to slide in the passageway, said .carriage being provided with a longitudinal slotv in, the front and lrear faces and a lateral slot in at least one of` said faces, a stop bar adjacent one end of each slot and, projecting for a short distance from the carriage, the stop bars being in substantial axial alignment and locatedv at diametrically opposed ends of the canriage means on the. head releasably holding the carriage against movement relative to the head, said means comprising a. ring rotatably mounted on each side of the head, a flat spring member interconnecting the rings, and a lugl narrower than the widthof the longitudinal slots projecting i11- Wardly from each of the rings to normally lock the carriage from sliding, said spring urging said rings to -la position whereby the lugs-are approximately diametrically' opposed, adjustable stop meansl mounted onthe housing to alternately engage each of the stopbars and thereby limit the extent of rotation of the head. and` toalternately engage and rotate. each. ofthe, lugs` over each of.l thelongitudinal slots at:` the limit. of head rotation tothereby release the carriage. from the, head at the` limit, of headrotation` and tothereafter enter the respective longitudinal! slot to therebylocki the headin. its limit position during, sliding of. the carriage, ar driving shaft journaledV int the head coaxial therewith, a crank arm. extending from: the shaft,v a shoe pivotall-y mounted adjacent the end of the. crank arm, said shoe, being slidinglyconnected to said carriage by means-of the lateral` slot thereby to rotate the head and carriage through the limits of head rotationand to thereafter actuate the carriage to sliderelative to the head, adresser arm mounted on the carriage, and a cutting tool carriedby the dresser arm.

6. A form dressing device las claimedin claimV 5. and further characterized in. that said adjustable stop means mounted onA the housing comprise a pair of oppositely disposed stop ringsrotatably mounted adjacentthe inner faces of the housing and encircling the head, said` rings being releasably locked against rotation relative tothe housing by. means of a band brake mechanism, a stop key having a width less than the width of the longitudinalslotswhereby to engage the stop bars and the longitudinali slots, and. a tingerelement dependingy from each ofthe -keys whereby` to engage the lugs.

7. A form. dressing device comprising a housing,l a' headrotatably journalledinthe housing, a carriage slidably mounted in the head, first stop means carried by the head abut-ting against each end of the carriagel to releasably hold the carriage against movementrelativeto the head, resilient means urgingsaid stop means intosaid abutting position, recess means in the carriage to receive said. first stop` means, a pair of peripherally adjustable stop elements carried: by the housing topositionsaid iirst stop means in registry with saidcarriage recess means at the respective limits of head rotation, second' stop means carried' by the carriage to engage one of said stop elements atthey respectivel limits of head rotation at; a position in registry with said carriage recess means, said stop elements andy said first stop means being receivable in saidv carriage recess means to. permit sliding of' the carriage, at driving shaft journall'ed in the head' coaxial. therewith, la crank arm extending from vthe shaft, a shoe pivotallymounted adjacent the outer end of the crank arm, said shoe being slidingly connected to the carriage by means of, a lateralslot in. one face of the carriage thereby- -torot-.ate the head and carriage through the limits of head rotation and to thereafter actuate the carriage to slide relative to the head, a dresser armi mount-- ed on [the carriage, and 1a cutting tooli carried bythe dresser arm.

References Cited' in the tile of thispatent UNITEDv STATES PATENTS 2,736,310- Baumann Feb. 28, 1-956 

